There are several situations in which motorized equipment operates using a supply of volatile fuel such as gasoline or kerosine. When equipment must be operated continuously in order to function properly, there is a need to replenish the supply of fuel quickly, safely, and possibly while the motorized equipment continues to function uninterrupted.
One such example of this kind of situation is when gasoline-powered chain saws are used to cut away brush and foliage during a forest fire, in order to create fire breaks. When a fire-fighter needs to refuel his saw, while acting in a dangerous environment with open flames near at hand, it is extremely crucial that transfer of flammable fuel is conducted in an extremely safe manner. Since gasoline is notoriously volatile, it is extremely important that refueling operations do not allow the release of volatile vapors that can ignite with potentially deadly consequences. Thus there is a need for an apparatus and method that can transfer volatile fluids in a manner which contains flammable vapors from the fuel as it is being transferred to the operating saw.
During operation in firefighting, the fuel tanks in gasoline powered saws such as Stihl saws build up excess pressure due to heat. The fuel tanks and caps in these saws are not capable of venting this excess pressure and when the cap is opened during the fueling process, fuel vapor is released under pressure causing a severe safety hazard. A method of safely relieving the pressure buildup inside the fuel tank before the cap is opened is necessary.
What is needed is a system that will eliminate the need for fuel or vapor to be exposed to the atmosphere during the refueling process. This method of refueling is called a “Dry Break System”. The basic system works on a fluid exchange principle, instead of a displacement principle. Typically, it is necessary to open both the fuel cap on the saw in addition to the cap on the fuel can, and then pour liquid fuel into the saw exposing both the fuel and vapor to the atmosphere. In contrast a dry break system is sealed. Once the fuel probe and the fuel tank are connected, fluid is simply exchanged from one to the other.
Thus, there is a need for a volatile liquids refueling apparatus which contains volatile fuel vapors during refueling operations.